Columbia Desert Parsley in the Landscape

Linda Chalker-Scott, Washington State University

Scientfic Name:  Lomatium columbianum
Common Name:  Columbia desert parsley, purple leptotaenia

Description:  Finely textured blue-green mounds topped with large clusters of wine-colored flowers. These large plants make a great backdrop for smaller rock garden species.

Native Habitat:  Basalt outcrops and shrub-steppe of the east Columbia gorge from south-central Washington to north-central Oregon.

Cultural Requirement

Soil:  Well drained, sandy or gritty soil. Deep soil bed needed to support large taproot.

Moisture Tolerance:  Once established will not need additional irrigation. Protect from excessive moisture in the winter.

Sun/Shade/Preference:  Full sun to part sun.

Transplanting:  Pot-to-pot or pot-to-garden. No problems reported.

Propagation:  Seeds should be collected in the early summer. Seeds can be planted immediately after collection. They will require cold conditions over winter to break dormancy, and it may take up to two years for germination.

Maintenance (pruning, fertilization, deadheading, division, irrigation, etc):  No special care needed. Avoid fertilizer, excess water.

Insect, disease, or other problems:  None reported.

Landscape Value

Use in the Landscape:  Rock gardens, other sunny, well-drained sites. This is a large plant and should be near the back of the garden.

Weediness/Invasive Potential:  None of concern.

Foliage:  Highly dissected light green to blue green leaves.

Flower:  Flowers in dense compound umbels, bright pink to purple.

Timing:  March-May.

Fruit:  Dry, flat, elliptical, winged fruit.

Form:  Herbaceous perennial forming large clumps.

Texture:  Fine, feathery.

Ultimate Size:  Up to 24 inches in height.

Rate of Growth:  Relatively slow; will not flower in the first year.

Suggested Plant Partners:  Other rock-garden species.

Availability:  Available through some native plant nurseries.

Cultivars:  None.

References: 

Bristol, M. 2018. Plant propagation protocol for Lomatium columbianum. University of Washington. [Accessed November 19, 2019]. https://courses.washington.edu/esrm412/protocols/LOCO.pdf

Knoke, D. and Giblin, D. ND. Lomatium columbianum – Columbia Gorge desert-parsley. Burke Herbarium Image Collection. [Accessed November 19, 2019]. http://biology.burke.washington.edu/herbarium/imagecollection/taxon.php?Taxon=Lomatium%20columbianum

Kruckeberg, A. and Chalker-Scott, L. 2019. Gardening with Native Plants of the Pacific Northwest, 3rd edition. University of Washington Press, Seattle, Washington.